<!DOCTYPE html>
<html lang="en">
	<head>
		<meta charset="UTF-8">
		<title>Title</title>
		<style type="text/css">
			[v-cloak] {
				display: none;
			}
		</style>
	</head>

	<body>
		<div id="app" v-cloak>
			{{str2}}
		</div>

		<script src="https://cdn.jsdelivr.net/npm/vue@2.5.17/dist/vue.js"></script>
		<script>
			new Vue({
				el: '#app',
				data: {
					str: '上古结绳而治,后世圣人易之以书契。千年来，数据始终影响着人们的生活。人类一直在探索，大数据时代来临之时使用何种工具用于改变用户利用数据的方式。',
					i: 0,
					timer: 0,
					str2: "",
				},
				methods: {
					typing() {
						if (this.i <= this.str.length) {
							this.str2 = this.str.slice(0, this.i++) + '_';
							this.timer = setTimeout(() => {
								this.typing();
							}, 200);
						} else {
							clearTimeout(this.timer)
						}
					}
				},
				mounted() {
					this.typing();
				}
			})
		</script>
	</body>
</html>